Electrophoresis Apparatus For Simultaneous Loading of Multiple Samples

ABSTRACT

The present invention includes apparatus for simultaneous loading of multiple samples for molecular separation, including a separation area with walls wherein at least one of the walls has apertures having loading sites, a gel located within the separation area, and a plurality of wells within the gel. The apertures are connected to the plurality of wells by channels structurally configured to convey samples from the apertures to the wells. The present invention further includes apparatus for electrophoresis separation having a substantially closed electrophoresis area, an electrophoresis gel located within the electrophoresis area, and multiple rows of wells within the electrophoresis gel, wherein the rows are arranged in a stagger format. A device is provided for delivering samples into wells for molecular separation, having a flat surface with a top side and a bottom side, multiple loading sites on the top side arranged in standard format, multiple apertures on the bottom side arranged in stagger format and leading to the wells, and a channel through the flat surface connecting the loading sites to the apertures. The present invention provides a method for simultaneous loading of multiple samples into an electrophoresis apparatus, including the steps of providing an electrophoresis apparatus having an area with walls defining the area and a gel within the area having multiple wells arranged in stagger format, wherein the walls include apertures having loading sites and channels structurally configured to direct samples into the wells, loading the samples into the loading sites with a standard multiple loading mechanism, and conveying the samples from the loading sites to the wells.

FIELD OF THE INVENTION

The present invention provides an apparatus for simultaneously loadingmultiple samples for conducting an electrophoresis test.

BACKGROUND OF THE INVENTION

A great deal of diagnostic procedures and laboratory research arecarried out wherein DNA, RNA or proteins are separated according totheir physical and chemical properties via electrophoresis. This processis widely used and has many applications. For example, electrophoresisis used to analyze DNA molecules according to their resultant size afterbeing digested by restriction enzymes. It is also used to analyze theproducts of a polymerase chain reaction (PCR).

In some instances, molecules are driven toward a capture layer, whichhas part of a molecular recognition pair e.g. antibody-antigen, DNA-DNAprobe, biotin-avidin, ligand-receptor, lectin-carbohydrate or others.Only specific parts of each pair of molecules that move through thecapture layer are captured (e.g., an antigen when the capture layercontains a specific antibody), while the non-specific molecules passthrough the layer unimpeded.

Electrophoresis separation is carried out in a separation medium, suchas a gel of agarose or acrylamide or a combination of the two. Agarosegels are cast in open trays and form a horizontal slab whereasacrylarnide gels are vertically cast between two glass plates.

Prior to electrophoresis separation, wells are introduced into the gelfor sample deposition by applying a comb-like structure prior to thesolidification or polymerization of the gel matrix. A row ofapproximately 8-15 wells is formed across one end of the gel.

In order to effect the electrophoresis separation, two opposite ends ofthe gel are exposed to a buffered solution which is connected byelectrodes, often made of platinum, to an electrical power source. Oncethe electrical power source is switched on, the electric field forcesnegatively charged molecules to move towards the anode and positivelycharged molecules to move towards the cathode. DNA is negatively chargedand therefore, in the agarose or acrylamide gels which provide sievingaction, DNA molecules move towards the anode at a rate which depends ontheir size, wherein the smaller the molecules the faster they move. Therunning distance should be long enough to allow sufficientdifferentiation between molecules.

It is desirable to visualize and to document the results of theelectrophoresis separation test. In electrophoresis separation of DNAmolecules, this has been done by immersing the gel slab after theelectrophoresis separation has been completed in a solution of afluorescent compound, such as ethidium bromide, which intercalateswithin DNA molecules and emits visible light when exposed to anultra-violet (UV) light. In order to document the results, a picture ofthe gel is taken through one of various photographic means.

Prior art electrophoresis systems are potential sources of contaminationto the working environment in which the tests are performed. The twomajor sources of contamination are ethidium bromide and PCR products.Ethidium bromide is a hazardous chemical due to its mutagenic activityand therefore, exposure to ethidium bromide may induce malignant tumors.PCR is an extremely sensitive method to the extent that a singlemolecule of DNA product from one PCR (out of the trillions of moleculesbeing produced) may interfere with the subsequent PCR such that it willproduce incorrect results.

Also, conventional electrophoresis is time consuming in terms ofpreparation and handling. This is particularly true when a large numberof samples are to be analyzed, and loading of samples is done one byone.

Several inventions have been directed towards eliminating contamination,such as U.S. Pat. No. 5,972,188, which describes the use of a membraneloader for gel electrophoresis; and an electrophoresis apparatus with acover, in U.S. Pat. Nos. 5,582,702, and 5,865,974 incorporated herein byreference. The apparatus is directed towards the running ofelectrophoresis separation, as well as detecting and analyzing theresults, within a self-contained, disposable unit.

Attempts have been made to reduce the time it takes to run anelectrophoresis separation as well by loading many samples at once.Further, simultaneous loading of samples could reduce contamination andhuman error. Standards in cell culture, ELISA and PCR analysis providedifferent sized plates, with corresponding pipettes for ease in sampleloading and analysis. For example, 96-well plates are typically used.Correspondingly, pipettes that fit this configuration are available andare widely used. Use of standard microtiter pipettes would greatlyreduce the loading time for electrophoresis.

Saito et al., in U.S. Pat. No. 5,785,835, address this issue byproviding an apparatus for loading of samples into wells within anexposed gel with standard pipettes. However, the testing apparatus haslimited resolution capacity since a running distance of only 0.8 cm isavailable. In U.S. Pat. No. 6,071,396 a gel-matrix layer is describedwith wells arranged for loading of samples with standard pipettes. Inthis patent, the running distance is increased by diagonally offsettingthe entire array of wells. U.S. Pat. No. 6,013,166 describes a methodfor reducing the linear dimension necessary for electrophoresisseparation in a micro-gel format.

In addition, several needle guide designs have been developed to aid inloading samples directly into wells in a way that would save time andprevent inaccuracies. For example, U.S. Pat. No. 5,656,145 provides aneedle guide for loading samples into a vertical slab gel. Similarly,U.S. Pat. No. 5,843,295 is directed towards a combination comb/loadingguide unit. In both of these designs, the loading sites are positioneddirectly on top of the wells so as to allow for simple, direct loadingof samples.

SUMMARY OF THE INVENTION

This invention provides, in accordance with an embodiment of the presentinvention, an apparatus for simultaneous loading of multiple samples formolecular separation, including a separation area with walls wherein atleast one of the walls has multiple apertures with loading sites,. a gellocated within the separation area, and a plurality of wells within thegel. The apertures are connected to the plurality of wells by channelsstructurally configured to convey samples from the apertures to thewells. In one embodiment, the loading sites are spaced at predeterminedintervals so as to conform with intervals between tips on a loader.

In one embodiment, the plurality of wells is arranged in rows, and therows are arranged in stagger format, providing a running distance formolecular separation which is longer than the distance between twoadjacent rows.

There is provided, in accordance with another embodiment of the presentinvention an apparatus for electrophoresis separation having asubstantially closed electrophoresis area, an electrophoresis gellocated within the electrophoresis area, and multiple rows of wellswithin the electrophoresis gel, wherein the rows are arranged in astagger format.

There is provided, in accordance with another embodiment of the presentinvention, a gel layer for molecular separation having a plurality ofwells within the gel layer. The wells are arranged in a plurality ofrows, and wells of one row are horizontally shifted from wells of aneighboring row by a predetermined distance. The horizontal shift isalternated from left to right, so as to form a staggered format of wellswithin the gel layer.

There is provided, in accordance with another embodiment of the presentinvention a device for delivering samples into wells for molecularseparation, having a flat surface with a top side and a bottom side,multiple loading sites on the top side arranged in standard format,multiple apertures on the bottom side arranged in stagger format andleading to the wells, and a channel through the flat surface connectingthe loading sites to the apertures.

There is provided, in accordance with another embodiment of the presentinvention an electrophoresis apparatus for non-weighted sampledeposition, including a substantially closed area, an electrophoresisgel with wells located within the electrophoresis area, and a non-liquidion source located within the gel, eliminating the need for weightingsamples before deposition into the wells.

There is provided, in accordance with another embodiment of the presentinvention a system for conducting electrophoresis separation includingan electrical power source, a substantially closed disposable cassettefor conducting an electrophoresis separation therein and havingconductive elements therein, and a support for supporting thesubstantially closed cassette and for connecting the electrical powersource to the conductive elements of the cassette, where one or moregels may be connected simultaneously. The cassette includes a body ofgel for carrying therein the electrophoresis separation, a plurality ofwells in the body of gel arranged in a stagger format and a plurality ofapertures having loading sites leading to the plurality of wells.

There is provided, in accordance with another embodiment of the presentinvention a method for treating water-absorbent plastic used forelectrophoresis devices, including the steps of placing thewater-absorbent plastic in a humidified environment and saturating thewater-absorbent plastic by leaving it in a humidified environment for apredetermined period of time.

There is provided, in accordance with another embodiment of the presentinvention a method for simultaneous loading of multiple samples into anelectrophoresis apparatus, including the steps of providing anelectrophoresis apparatus having an area with walls defining the areaand a gel within the area having multiple wells arranged in staggerformat, wherein the walls include apertures having loading sites andchannels structurally configured to direct samples into the wells,loading the samples into the openings with a standard multiple loadingmechanism, and directing the samples from the apertures to the wells.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description taken in conjunction with theappended drawings in which:

FIGS. 1 and 2 are schematic illustrations of an electrophoresisapparatus in accordance with an embodiment of the present invention;

FIGS. 3A-3D are geometric illustrations of configurations of wells andapertures and loading sites according to one embodiment of the presentinvention;

FIGS. 4A-4C are geometric illustrations of configurations of wells andapertures and loading sites according to another embodiment of thepresent invention;

FIG. 5 is a schematic illustration of a channel configuration inaccordance with one embodiment of the present invention;

FIG. 6 is a schematic illustration of a channel configuration inaccordance with another embodiment of the present invention;

FIGS. 7A and 7B are schematic illustrations of channel configurations inaccordance with further embodiments of the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Reference is made to FIGS. 1 and 2, which illustrate an electrophoresisdisposable cassette, generally referenced 10. FIG. 1 shows an externalconfiguration of cassette 10, while FIG. 2 shows a cross-sectional view.Cassette 10 is a closed disposable cassette used for a singleelectrophoresis test, and includes all the chemical compounds requiredfor driving the electrophoresis separation and for enablingvisualization of its results when DNA as well as RNA or proteinmolecules have been separated, as will be described hereinbelow.

As shown in FIG. 1, cassette 10 comprises a three dimensional separationarea 11 having bottom wall and side walls, referenced 12 and 14respectively, and a top wall 16 having a specified thickness. Cassette10 is substantially closed in that it is enclosed by walls 12, 14 and16, but it also comprises vent holes and apertures as will be describedhereinbelow. In one embodiment, the thickness ranges from 0.1-10 mm. Inanother embodiment, the thickness is 1.5 mm. Cassette 10 as shown inFIG. 1 has a specified length, width and height. In one embodiment, thelength ranges from 100-200 mm, the width ranges from 50-150 mm and theheight ranges from 1-10 mm. In a preferred embodiment, length, width andheight are 160 millimeters (mm), 100 mm and 6 mm, respectively. Inanother preferred embodiment, length, width and height are 130 mm, 130mm and 6 mm, respectively.

Bottom wall 12 and top wall 16 are preferably made of any suitable UVtransparent material, such as the TPX plastic commercially availablefrom MITSUI of Japan or the Polymethylmethacrylate (PMMA) plasticcommercially available from Repsol Polivar S.P.A. of Rome, Italy.Cassette 10 may include vent holes 32 and 34 to allow for gaseousmolecules that might be generated due to the electrochemical reaction(e.g., oxygen and/or hydrogen) to be released. In one embodiment, ventholes range in diameter from 0.5-2 mm. In a preferred embodiment, ventholes are 1 mm in diameter.

As seen in the cross section illustration (IV-IV) of FIG. 2, area 11comprises a gel matrix 18 which may be any suitable gel matrix forelectrophoresis, such as an agarose gel or a gel made of acrylamide(available from, for example, Sigma, St. Louis, Mo., USA). A pluralityof wells 36 may be introduced into gel 18, by using a “comb” having arow of protruding teeth positioned so that the teeth project into thegel layer while it sets. In one embodiment, the plurality of wellsranges from 1-200 wells. In another embodiment, the plurality of wellsranges from 8-12 wells. In another embodiment, the plurality of wellsincludes 96 wells.

When the gel has set, the comb is removed to leave a row of wells 36, orholes, in the layer. In one embodiment, wells 36 are dimensions of 0.5-5mm wide, 1-5 mm long, and 3-5 mm deep, and are used to introduce samplesof the molecules to undergo molecular separation. One row or severalrows may be formed. In one embodiment of the present invention, 12 rowsof 8 wells per row are formed, and are arranged in a stagger format, asshown in FIG. 1 and described more fully below. In another embodiment, 8rows of 12 wells per row are formed and may also be arranged in astagger format. For one embodiment of the present invention, top wall 16has apertures used as loading sites 41, as described more fully below.

In addition, cassette 10 may optionally include a capture layer 37including part of a molecular recognition pair for separating samplesaccording to binding properties. Capture layer 37 is immobilized withingel 18, and is fabricated with resins to which the binding site of amolecule of interest will covalently bind. Some examples include avidinon acrylic beads, biotin on cross linked beaded agarose and others. Theresins are mixed with agarose or other materials and poured as layersinto gel 18. Alternatively, acrydite™ (available from MosaicTechnologies, Waltham, Mass., USA) may be used. Acrydite™ is aphosphoramide that is capable of copolymerization with acrylamide, andit can be used to introduce copolymerizable groups on the 5′ terminus ofany oligonucleotide probe. To make the capture layer, Acrydite™oligonucleotide capture probes may be mixed with acrylamide solutionsand polymerized into gel layers.

The capture electrophoresis technique provides concentrated signals,saves time and saves material. One or multiple capture layers may beused. This technique may be performed on its own, or in combination witha standard size electrophoresis separation.

It is desirable to visualize and to document the results of theelectrophoresis separation test. In electrophoresis separation of DNAmolecules, this has been done by immersing the gel slab after theelectrophoresis separation has been completed in a solution of afluorescent compound which emits visible light when exposed to an ultraviolet (UV) light. According to one embodiment of the present invention,the samples or the gel interact with ethidium bromide or otherfluorescent dyes. In this way, the results may be viewed in situ,without the need for exposing the samples to contamination by removingthe gel from the enclosed area 11.

According to another embodiment of the present invention, various typesof light sources may be used. In one embodiment, a light source ofadjustable or non-adjustable wavelengths may be used. The light sourcemay include visible or non-visible light.

Alternatively a colorimetric dye, such as Methylene Blue may be added tothe samples, the gel, or the ion reservoir and may interact with themolecules undergoing electrophoresis separation, so as to enablevisualization of the results without the need for a UV light source.

Area 11 also comprises two conductive electrodes referenced 21 and 23which, when connected to an external direct current (DC) electricalpower source, provide the electric field required to driveelectrophoresis separation. In the illustrated embodiment, electrode 21is the cathode and electrode 23 is the anode. The system may alsoinclude a support for connecting conductive elements of cassette 10 tothe power source. In one embodiment, the support is configured toconnect to one or more gels simultaneously. Further, the systemoptionally includes a camera for documentation.

In one embodiment, the gel 18 and the conductive electrodes 21 and 23are in contact with non-liquid ion sources such as ion exchange matricesas described in U.S. Pat. Nos. 5,582,702 and 5,865,974.

It should be noted that since plastics used as cassette material aresometimes water absorbent, they may be pre-treated by placement in ahumidified environment and saturation by leaving it for a predeterminedperiod of time so as to avoid later water adsorption or uptake ofliquid, thereby keeping the gel intact. In one embodiment, the period oftime ranges from 1-72 hours. In another embodiment, the period of timeranges from 1-20 days. In another embodiment, the period of time is atleast 10 days. In a preferred embodiment, the period of time is 10 days.

It should be noted that in conventional electrophoresis, samples must beweighted so that they sink through the buffer to the bottom of thewells. This is generally accomplished by combining a substance such asGlycerol, Sucrose, or Ficoll polymer with the sample. It will beappreciated that in one embodiment of the present invention, there is noliquid buffer present in the vicinity of the wells, and instead, anon-liquid ion source is located within said gel. Thus, the step ofweighting samples before deposition into said wells may be eliminated,thereby decreasing the time necessary to perform an experiment.

Reference is now made to FIGS. 3A-3D, taken together with 4A-4C, whichshow embodiments of loading sites 41 and outlet apertures 39 on twosides of wall 16. It will be appreciated that in one embodiment, wall 16refers to the top wall, or the cover, of the apparatus. In anotherembodiment, other walls are used, such as side walls. Wall 16 should beconsidered as a flat surface with a top side and a bottom side. FIGS. 3Aand 4A show views from the top side of wall 16. FIGS. 3B and 4B showviews from the bottom side of wall 16. FIG. 3C shows a three-dimensionalview of a portion of wall 16. FIGS. 3D and 4D show cross-sectional viewsof a portion of wall 16.

Stagger format of outlet apertures 39, located on the bottom side ofwall 16, corresponds to stagger format of wells 36 within a layer of gel18, as depicted in FIGS. 3B and 4B. That is, wells of one row arehorizontally shifted from wells of a neighboring row by a predetermineddistance. In one embodiment, the predetermined distance is in the rangeof 0.05-20 mm. In another embodiment, the predetermined distance is 4.5mm. The horizontal shift occurs in alternating directions from left toright, so as to form a staggered format.

Thus, when electrophoresis separation takes place, the available runningdistance between adjacent wells 36 in the direction of electrophoresisseparation is from 8-20 mm. In one embodiment, the available runningdistance is up to 18 mm, as shown by arrow 43. This amount is doublewhat would be available without stagger formatting, greatly increasingthe potential for larger sized molecules to be separated. If wells 36were arranged according to a standard format, and not a stagger format,samples in each row would have a running distance of less than 1 cm,whereas in the configuration illustrated in FIG. 3B, twice that distanceis available since samples can run between wells 36 of the next row.

In the embodiment shown in FIG. 3A, inlet apertures 38 have loadingsites 41 located on the edges, all on the top of wall 16 of cassette 10.Loading sites 41 are configured either linearly (one row), or in ageometrical arrangement of columns and rows, typically in a rectangulararrangement. In one embodiment, loading sites 41 are spaced atpredetermined intervals so as to conform with intervals between tips ona loader. “Loader” refers to a mechanism used to load samples, such as amicro-titer pipette, as described hereinbelow. Multiple loadingmechanisms allow for many samples to be loaded at once. Thus, thespacing between loading sites can vary, and may be configured to conformwith intervals on any type of loader. In one embodiment, thepredetermined intervals include 0.5-2 mm spacings. In a preferredembodiment, the predetermined intervals include 9 mm spacings, so as toconform with a micro-titer multi-pipette loader for 96 wells. In anotherembodiment, predetermined intervals include 0.001-1 mm spacings, so asto allow for a micro-scale system.

The shape of loading sites 41 may vary, but they are typically circular,so as to fit the end of a loader tip. A standard multiple loadingmechanism such as a microtiter multi-pipette loader available from, forexample, Eppendorf Scientific, Inc., Westbury, N.Y., USA may be used,thus enabling simultaneous loading of as many samples as can fit in thepipette. Thus, for a 96-well configuration, loaders are available from,for example, Beckman Coulter, Inc., Fullerton, Calif., USA, that wouldenable loading of 96 samples all at the same time, or loading of 8 or 12samples at a time. Similar models might be available for the otherformats as well.

Loading sites 41, either located on the edges of inlet apertures 38 asin FIG. 3A, or alone, as in FIG. 4A, are not directly above outletapertures 39, which lead into wells 36. Therefore, samples must beconveyed to wells 36, either by use of an incline, or by some othermethod, as described hereinbelow. Variations of the describedembodiments are possible, for example, apertures and loading siteslocated in walls other than wall 16, such as side walls which in avertical gel would form the top wall.

As shown in FIGS. 3D and 4C, channels 40 connect loading sites 41 tooutlet apertures 39. Channels 40 are formed from structural adaptationsof wall 20 connecting loading site 41 to outlet aperture 39 so as toallow for the flow of a sample from loading site 41 to outlet aperture39. Channels 40 are structurally configured in such a way so as toconvey samples into wells 36. In one embodiment, channel 40 comprises anincline. In another embodiment, channel 40 comprises another feature tohelp convey the sample, such as a magnetic or electrical property.

Reference is now made to FIG. 5, which shows an embodiment of thepresent invention. A wide loading site 41 is portrayed above outletaperture 39. Thus, the shape and/or size of loading site 41 differs fromthe shape and/or size of outlet aperture 39. In this example, channel 40is configured in an irregular shape so as to allow for the sample to bedirected into outlet aperture 39, even though application of the samplemay not occur directly in line with outlet aperture 39.

Reference is now made to FIG. 6, which shows a further embodiment of thepresent invention. Outlet aperture 39 and loading site 41 are indirectlyaligned with one another. Since loading site 41 is not located directlyabove outlet aperture 39, an incline in channel 40 provides direction ofthe sample into outlet aperture 39, and then into well 36.

Reference is now made to FIGS. 7A and 7B, which are illustrations offurther embodiments of the present invention. In FIG. 7A, one loadingsite 41 leads to multiple outlet apertures 39, and in FIG. 7B, multipleloading sites 41 lead to one outlet aperture 39. Thus, as shown in FIG.7A, multiple tests can be performed on a sample after a single pipetteapplication, reducing the sample loading time. This is accomplished bychannel 40 having a branched configuration. Alternatively, if largeramounts of samples are needed, multiple amounts may be delivered to onewell 36, as shown in FIG. 7B, without changing the settings on thepipettes. This, too, is accomplished by a structural channel 40configuration. Many other configurations are possible.

It will be appreciated that the embodiments described hereinabove aredescribed by way of example only and that numerous modificationsthereto, all of which fall within the scope of the present invention,exist. For example, gels may be either vertical or horizontal. Inaddition, apertures may be on the side wall of the apparatus, ratherthan directly on the top cover. In one embodiment, the entire system isin a microscale range, in which case all the dimensions describedhereinabove are reduced by a factor of 10-100.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather, the scope of the present invention isdefined only by the claims that follow:

1-95. (canceled)
 96. An apparatus for electrophoresis separation, theapparatus comprising: a substantially closed electrophoresis area; anelectrophoresis gel located within the electrophoresis area; a wall incontact with the electrophoresis gel, wherein the wall comprises aplurality of loading sites and wherein the loading sites are arranged inat least two non-staggered rows; and a plurality of wells within theelectrophoresis gel.
 97. The apparatus of claim 96, further comprisingat least one ion exchange matrix.
 98. The apparatus of claim 96, whereinthe plurality of loading sites are configured in a rectangulararrangement.
 99. The apparatus of claim 96, wherein the plurality ofloading sites are spaced at a predetermined interval.
 100. The apparatusof claim 99, wherein the predetermined intervals comprises loading sitespacings in the range of 0.001-20 millimeters.
 101. The apparatus ofclaim 96, wherein the wall forms part of a substantially closedcassette, and wherein the cassette contains the electrophoresis geltherewithin and the cassette comprises electrically conductingelectrodes for performing the electrophoresis separation.
 102. A systemfor conducting an electrophoresis separation, the system comprising: anelectrical power source; a substantially closed disposable cassetteconducting the electrophoresis separation therein, wherein the cassettecontains electrically conductive electrodes and a body ofelectrophoresis gel; a plurality of wells in the body of electrophoresisgel; a plurality of loading sites arranged in at least two non-staggeredrows, and wherein the electrical power source is connected to theelectrically conductive electrodes of the cassette.
 103. The system ofclaim 102, further comprising a support for connecting the electricalpower source to the conductive electrodes of the substantially closecassette.
 104. The apparatus of claim 102, further comprising at leastone ion exchange matrix.
 105. The system of claim 101, furthercomprising a light source, thereby enabling visualization of theelectrophoresis separation while said cassette is in situ.
 106. Thesystem of claim 102, wherein the support is configured to connect to oneor more gel simultaneously.
 107. The system of claim 102, wherein theplurality of loading sites are configured in a rectangular arrangement.108. The system of claim 102, wherein the plurality of loading sites arespaced at a predetermined interval.
 109. The system of claim 102,wherein the predetermined interval comprises loading site spacings inthe range of 0.001-20 millimeters.
 110. A method for molecularseparation, the method comprising the steps of: providing an apparatushaving a separation chamber having walls defining the separation chamberand a gel within the chamber, wherein said walls comprise a plurality ofloading sites arranged in at least two non-staggered rows; loading atleast one sample into at least one row of the plurality of loadingsites; providing an electrical current through said separation chamberso as to allow for separation of the sample according to predefinedproperties, wherein the predefined properties are molecular size,binding properties, or a combination of molecular size and bindingproperties.
 111. The method of claim 110, wherein the sample is loadedinto the plurality of loading sites wherein the plurality of loadingsites are configured in a rectangular arrangement.
 112. The method ofclaim 110, wherein the sample is loaded into the plurality of loadingsites wherein the plurality of loading sites are spaced at apredetermined interval.
 113. The method of claim 110, wherein the sampleis loaded into the plurality of loading sites wherein the predeterminedinterval comprises loading site spacings in the range of 0.001-20millimeters.
 114. The method of claim 110, further comprisingvisualizing the separated sample.
 115. The method of claim 110, furthercomprising visualizing the separated sample in situ.